Pentagon grounds F-35 fleet after runway fire

By CNN Staff

Updated 3:06 PM ET, Fri July 4, 2014

U.S. military's fighter fleet9 photos

An F-15E Strike Eagle was designed for long-range, high-speed interdiction without relying on escort or electronic warfare aircraft. It was derived from the F-15 Eagle, which was developed to enhance U.S. air superiority during the Vietnam War.

Hide Caption

1 of 9

U.S. military's fighter fleet9 photos

A F-22 Raptor flies over Marietta, Georgia, home of the Lockheed Martin plant where it was built. The F-22 is the only fighter capable of simultaneously conducting air-to-air and air-to-ground combat missions.

Hide Caption

2 of 9

U.S. military's fighter fleet9 photos

F-16 Fighting Falcons are parked at the Aerospace Maintenance and Regeneration Center in Tucson, Arizona, on December 11, 2004. General Dynamics (which was later sold to Lockheed) delivered the U.S. Air Force its first F-16As in 1979. More than 4,500 of the fighters have been built, and they are used by more than 20 nations in addition to the United States.

Hide Caption

3 of 9

U.S. military's fighter fleet9 photos

A F-35C conducts a test flight over the Chesapeake Bay on February 11, 2011. Inspections of F-35 engines have been ordered after a runway fire at Eglin Air Force Base on June 23. The F-35 Lightning II has been beset by delays and cost overruns in the years since its introduction.

An F/A-18E Super Hornet from the Sunliners of Strike Fighter Squadron 81 taxis onto a catapult before launching from the flight deck of the aircraft carrier USS Carl Vinson.

Hide Caption

6 of 9

U.S. military's fighter fleet9 photos

An F/A-18 Hornet is pictured aboard the USS George H.W. Bush on May 19, 2009. The F/A-18 Hornet, a late-'70s contemporary of the Air Force's F-16 Fighting Falcon, became the workhorse of U.S. carrier-based air power and still supplements the Navy's and Marines' more current fleet of F/A-18E and F/A-18F Super Hornets. It is designed as both a fighter and an attack aircraft.

Hide Caption

7 of 9

U.S. military's fighter fleet9 photos

Pilots perform daily flight checks on their F-5E/F Tiger aircraft in Key West, Florida, on January 7, 2005. The Vietnam-era aircraft -- one of several offshoots of the original Northrup F-5s that went into service in the early 1960s -- is used to simulate adversary aircraft in training.

Hide Caption

8 of 9

U.S. military's fighter fleet9 photos

A AV-8B Harrier lands on board the USS Nassau on April 14, 1999, after a strike mission into Kosovo. The AV-8B Harrier is a single-engine ground-attack aircraft capable of vertical or short takeoff and landing. Though production of the aircraft ceased in 2003, the U.S. Marine Corps is looking at systems enhancements and plans to continue using Harriers well into the next decade.

Hide Caption

9 of 9

Story highlights

Fire took place June 23 at Eglin Air Force Base

The Joint Strike Fighter is grounded for engine inspections

The F-35 program has been beset by delays and cost overruns over the years

The Pentagon's most expensive weapons program ever, the F-35 warplane, is grounded again.

Developed at a cost of nearly $400 billion so far and beset for years by cost overruns and delays, the so-called Joint Strike Fighter was put down temporarily this week following a runway fire at Eglin Air Force Base in Florida. No one was hurt.

Pentagon spokesman Rear Adm. John Kirby said the cause of the June 23 incident remains under investigation, and the timing of when they might take off again is unclear.

"Additional inspections of F-35 engines have been ordered, and return to flight will be determined based on inspection results and analysis of engineering data," Kirby said.

Engine maker Pratt & Whitney said in a statement that it was working with Air Force investigators to inspect all engines in the fleet. It declined further comment.

Lead contractor Lockheed Martin also said it was working with investigators. It is producing variants of the plane for the U.S. Navy, Marines and Air Force.

The Pentagon wants more than 2,400 ultimately, while hundreds more are expected over time to go to allies such as South Korea, Japan and Australia.

More than 100 planes have been built so far, most for testing, but the program is still in its development and training phases.

The military says the stealthy fighter will be "the most affordable, lethal, supportable and survivable aircraft ever to be used" by so many services worldwide.

While all models have been grounded in the past for various problems, the version for the Marines, the F-35B, has had more issues. Experts say that's mainly due to its design for shorter takeoffs and vertical landings.

Richard Aboulafia, a Teal Group analyst, said every component of the F-35 overall "is pushing the frontiers of technology" as engineers combine extraordinary engine power with a lighter weight design.

He said the program has made gradual progress in recent years where glitches get resolved pretty quickly compared with 18 to 24 months ago, when setbacks seemed to come one right after another.

The F-35 is due to make a much-anticipated appearance at the international air show at Farnborough airport in Hampshire, England, in coming weeks. Aboulafia said a no-show could indicate a more serious problem with the engine.